In material removal devices and processes, commonly referred to as material machining or simply machining, a cutting head, typically in the form of a carbide cutting wheel or bit, or in more advanced machining techniques, a laser head, is placed in contact or close proximity with the material to be machined. The cutting head is then moved along a path of travel across the material until the desired material is removed and/or altered from its original condition. In modern machining equipment, the cutting path and other parameters are programmed into a computer numerically controlled (CNC) machining device executing a computer program that, in one function, guides the cutting head along the desired path of travel.
In conventional and CNC machining devices, it is vital that the expensive and often delicate cutting heads, whether a cutting bit or a laser, not be subject to a path of travel that would contact portions of the material that are not to be machined or other surrounding equipment, for example, fixtures that may position and secure the material to be machined to a table or workstation. Any such unintended or unauthorized contact of the cutting head with these areas or equipment can damage or misalign the cutting head and/or the potentially delicate material that is to be machined.
In order to avoid unintended contact of the cutting head with surrounding equipment or portions of the material, safety zones are often established to prevent the cutting head from entering into certain areas where such undesirable contact of the cutting head may occur. Depending on the material to be machined, for example a planer or non-planar material surface, or where complex fixturing is used, these safety or restricted zones may take the form of two-dimensional x-y coordinate areas or may be three-dimensional zones having an x-y area as well as a z-coordinate height aspect.
Definition of these safe or restricted zones, where it is undesirable for the cutting head to travel or pass through, typically has to be defined on a job-by-job basis as either the material to be machined or the fixtures used to position or secure the object are different. In CNC machines, these coordinates, often three-dimensional, need to be identified in the coordinate system used by the cutting machine and then input into the computer program. Where many safety zones or safety zones with complex configurations are required, identification of the coordinates or boundaries of the safety zones, and input of these coordinates, can be very tedious and time consuming.
Therefore, it would be beneficial to develop a method for establishing safety or restricted zones in machining devices, for example laser machining devices, that is more efficient and takes less time than prior methods. It would be further advantageous to develop a method for identifying three dimensional coordinates defining the boundaries of desired restricted zones and importing them into the computer program, or programs, of computer numerically controlled machining devices.